suanPan-manual
  • Introduction
  • Basic
    • Obtain Application
    • Configure Application
    • Perform Analysis
    • Model Syntax
    • Model Structure
    • Tweak Performance
    • Compile Application
    • Build Documentation
    • Architecture Design
    • On Clusters
  • Example
    • Developer
      • element template
      • material template
    • Solid
      • wave propagation
    • Geotechnical
      • triaxial compression of sand
      • slope analysis
    • Structural
      • Statics
        • bending of a cantilever beam
        • bifurcation of a cantilever beam
        • double-edge notched specimen
        • lees frame
        • notched beam under cyclic loading
        • rc section analysis
        • truss roof
        • uniform tension of a rubber specimen
        • thin-walled section analysis for frame structures
        • calibration of subloading surface model
      • Dynamics
        • bouncing of a ball
        • mass-spring-dashpot system
        • dynamic analysis of a portal frame
        • elemental damping
        • particle collision
        • response history analysis of an elastic coupled wall
        • multi-support excitation
        • triple pendulum
        • computing response spectrum
        • integrate with python
        • process ground motion
      • Hybrid
        • vibration of a displaced beam
      • Buckling
        • buckling analysis of a cantilever beam
      • Contact
        • contact between beam and block
        • contact in 3d space
      • Optimization
        • evolutionary structural optimization
      • Isogeometric Analysis
        • linear analysis of a single element
    • Miscellaneous
      • batch execution for automation
  • Command Collection
    • Define
      • amplitude
      • bc
      • domain
      • element
      • expression
      • file
      • generate
      • group
      • import
      • initial
      • load
      • material
      • modifier
      • node
      • recorder
      • section
    • Configure
      • analyze
      • converger
      • criterion
      • integrator
      • precheck
      • step
    • Process
      • benchmark
      • clear
      • command
      • enable
      • exit
      • materialtest
      • materialtestbyload
      • sectiontest
      • peek
      • plot
      • protect
      • pwd
      • reset
      • save
      • set
      • upsampling
      • sdof_response
      • response_spectrum
  • Amplitude
    • Amplitude
    • Special
      • NZStrongMotion
    • Universal
      • Combine
      • Constant
      • Decay
      • Linear
      • Modulated
      • Tabular
      • TabularSpline
      • Trig
  • Constraint
    • MPC
    • ParticleCollision
    • RigidWall
    • RestitutionWall
    • FixedLength
    • MaxForce
    • NodeLine
    • NodeFacet
    • Embed2D
    • Embed3D
    • LJPotential2D
    • MaximumGap2D
    • MinimumGap2D
    • MaximumGap3D
    • MinimumGap3D
  • Converger
    • Converger
    • Absolute
      • AbsDisp
      • AbsError
      • AbsIncreDisp
      • AbsIncreAcc
      • AbsIncreEnergy
      • AbsResidual
    • Other
      • FixedNumber
      • Logic
    • Relative
      • RelDisp
      • RelError
      • RelIncreDisp
      • RelIncreAcc
      • RelIncreEnergy
      • RelResidual
  • Criterion
    • Criterion
    • MaxDisplacement
    • MaxHistory
    • MaxResistance
    • MinDisplacement
    • MinResistance
    • StrainEnergyEvolution
  • Element
    • Beam
      • B21
      • B21E
      • B21H
      • B31
      • B31OS
      • EB21
      • EB31OS
      • F21
      • F21H
      • F31
      • NMB21
      • NMB21E
      • NMB31
      • MVLEM
      • Orientation
    • Cube
      • C3D20
      • C3D4
      • C3D8
      • C3D8I
      • CIN3D8
      • DC3D4
      • DC3D8
    • Membrane
      • Couple Stress
      • Phase Field
        • DCP3
        • DCP4
      • Axisymmetric
        • CAX3
        • CAX4
        • CAX8
      • Plane
        • CP3
        • CP4
        • CP4I
        • CP5
        • CP6
        • CP7
        • CP8
      • Mixed
        • PS
        • QE2
      • Drilling
        • Allman
        • GCMQ
        • GQ12
      • Infinite
        • CINP4
      • Geotechnical
        • PCPE4DC
        • PCPE4UC
        • PCPE8DC
        • PCPE8UC
      • Membrane
    • Modifier
      • Modifier
      • ElementalLee
      • ElementalNonviscous
      • LinearViscosity
    • Patch
      • Patch
      • PatchCube
      • PatchQuad
    • Plate
      • DKT3
      • DKT4
      • Mindlin
    • Shell
      • DKTS3
      • DKTS4
      • S4
      • SGCMS
      • ShellBase
    • Special
      • Contact2D
      • Contact3D
      • Damper01
      • Damper02
      • Embedded2D
      • Embedded3D
      • Joint
      • Mass
      • SingleSection
      • Spring01
      • Spring02
      • Tie
      • TranslationConnector
    • Truss
      • T2D2
      • T2D2S
      • T3D2
      • T3D2S
  • Group
    • CustomNodeGroup
    • NodeGroup
    • ElementGroup
    • GroupGroup
  • Integrator
    • Implicit
      • Linear
      • BatheTwoStep
      • GeneralizedAlpha
      • OALTS
      • GSSSS
      • Newmark
        • LeeNewmark
        • LeeElementalNewmark
        • LeeNewmarkFull
        • LeeNewmarkIterative
        • Newmark
        • RayleighNewmark
        • WilsonPenzienNewmark
        • NonviscousNewmark
    • Explicit
      • Tchamwa
      • BatheExplicit
      • GeneralizedAlphaExplicit
  • Material
    • Guide
      • Metal
      • Customisation
    • Material1D
      • Concrete
        • ConcreteCM
        • ConcreteExp
        • ConcreteTsai
        • ConcreteTable
        • ConcreteK4
      • Degradation
        • Degradation
        • CustomStrainDegradation
        • CustomStressDegradation
        • Dhakal
        • TrilinearStrainDegradation
      • Elastic
        • BilinearElastic1D
        • Elastic1D
        • AsymmElastic1D
        • MultilinearElastic1D
        • PolyElastic1D
        • NLE1D01
        • Sinh1D
        • Tanh1D
        • CustomElastic1D
      • Hysteresis
        • AFC
        • AFCN
        • BilinearOO
        • BilinearPO
        • BoucWen
        • BWBN
        • Flag
        • MPF
        • MultilinearOO
        • MultilinearPO
        • RambergOsgood
        • SimpleHysteresis
        • SlipLock
        • SteelBRB
        • Trivial
        • Gap01
      • Viscosity
        • Kelvin
        • Maxwell
        • NonlinearViscosity
        • BilinearViscosity
        • CustomViscosity
        • Viscosity01
        • Viscosity02
        • CoulombFriction
        • Nonviscous01
      • vonMises
        • Subloading1D
        • ArmstrongFrederick1D
        • AFCO1D
        • Bilinear1D
        • BilinearMises1D
        • CustomGurson1D
        • CustomMises1D
        • ExpGurson1D
        • ExpMises1D
        • Mises1D
        • Multilinear1D
        • NonlinearGurson1D
        • VAFCRP1D
    • Material2D
      • AxisymmetricElastic
      • Concrete21
      • Concrete22
      • DuncanSelig
      • Elastic2D
      • Rebar2D
    • Material3D
      • CamClay
        • BilinearCC
        • ExpCC
        • NonlinearCamClay
        • ParabolicCC
      • Concrete
        • CDP
        • CDPM2
        • Rebar3D
        • TableCDP
        • CustomCDP
      • Damage
        • IsotropicDamage
        • LinearDamage
      • DruckerPrager
        • BilinearDP
        • ExpDP
        • CustomDP
        • NonlinearDruckerPrager
      • Elastic
        • BlatzKo
        • IsotropicElastic3D
        • IsotropicNonlinearElastic3D
        • MooneyRivlin
        • NLE3D01
        • OrthotropicElastic3D
        • Yeoh
      • Hoffman
        • BilinearHoffman
        • ExpHoffman
        • CustomHoffman
        • NonlinearHill
        • NonlinearHoffman
        • TimberPD
      • Sand
        • SimpleSand
        • DafalisaManzari
      • vonMises
        • ArmstrongFrederick
        • BilinearJ2
        • BilinearPeric
        • CustomGurson
        • TableGurson
        • CustomJ2
        • ExpGurson
        • ExpJ2
        • MultilinearJ2
        • NonlinearGurson
        • NonlinearJ2
        • NonlinearPeric
        • PolyJ2
        • VAFCRP
        • Subloading
    • MaterialOS
      • ElasticOS
    • Wrapper
      • Axisymmetric
      • Laminated
      • Parallel
      • PlaneStrain
      • PlaneSymmetric
      • PlaneStress
      • Rotation2D
      • Rotation3D
      • Sequential
      • Stacked
      • Uniaxial
      • OS146
      • OS146S
      • Substepping
  • Recorder
    • Recorder
    • OutputType
  • Section
    • Code
      • EU
      • NZ
      • US
    • Section1D
      • Circle1D
      • Fibre1D
      • Rectangle1D
      • TrussSection
    • Section2D
      • Bar2D
      • Box2D
      • Circle2D
      • CircularHollow2D
      • Fibre2D
      • HSection2D
      • ISection2D
      • Rectangle2D
      • TSection2D
    • Section3D
      • Bar3D
      • Box3D
      • Circle3D
      • CircularHollow3D
      • Fibre3D
      • ISection3D
      • Rectangle3D
      • TSection3D
    • SectionOS
      • Cell3DOS
      • Fibre3DOS
    • SectionNM
      • SectionNM
      • NM2D1
      • NM2D2
      • NM2D3
      • NM2D3K
      • NM3D1
      • NM3D2
      • NM3D3
      • NM3D3K
  • Solver
    • BFGS
    • MPDC
    • Newton
    • AICN
    • Ramm
  • Step
    • Overview
    • ArcLength
    • Buckle
    • Dynamic
    • Frequency
    • Optimization
    • Static
  • Developer
    • Prerequisites
    • C Style Interface
      • material
    • CPP Style Interface
      • material
      • element
      • constraint
Powered by GitBook
On this page
  • Syntax
  • History Variable Layout
  • Theory
  • Determination of Parameters
Edit on GitHub
  1. Material
  2. Material1D
  3. Concrete

ConcreteExp

PreviousConcreteCMNextConcreteTsai

Last updated 1 year ago

Objective Concrete Model

The ConcreteExp model uses the exponential functions from the Barcelona model (Lubliner, 1989) as the backbones. The main advantage is now the area under the backbone has an upper bound and can be explicitly integrated. By associating this value with objective quantities, it is possible to obtain a uni-axial concrete model that supports objective response.

Syntax

material ConcreteExp (1) (2) (3) (4) (5) (6) (7) (8) [9] [10]
# (1) int, unique tag
# (2) double, elastic modulus
# (3) double, f_t
# (4) double, a_t
# (5) double, g_t
# (6) double, f_{c,m}
# (7) double, a_c
# (8) double, g_c
# [9] double, middle point, default: 0.2
# [10] double, density, default: 0.0

History Variable Layout

Since it is derived from the model, they share the same history variable layout.

Theory

For both tension and compression, the following equation is used for the backbone.

σf=(1+a)exp⁡(−bεp)−aexp⁡(−2bεp)\dfrac{\sigma}{f}=\left(1+a\right)\exp\left(-b\varepsilon_p\right)-a\exp\left(-2b\varepsilon_p\right)fσ​=(1+a)exp(−bεp​)−aexp(−2bεp​)

where aaa and bbb are two material properties that control the shape of the backbone. For tension, a<1a<1a<1. For compression a>1a>1a>1.

The area under the backbone is

g=a+22bf.g=\dfrac{a+2}{2b}f.g=2ba+2​f.

So for a fixed ggg, bbb can be computed as

b=a+22gf.b=\dfrac{a+2}{2g}f.b=2ga+2​f.

The model accepts gtg_tgt​ and gcg_cgc​ in order to obtain objective results.

The parameters ftf_tft​ and fcf_cfc​ are elastic limits of tension and compression respectively. However, the maximum strength fc,mf_{c,m}fc,m​ are taken as inputs since for compression there is a hardening response.

It could be derived that

fcfc,m=4ac(1+ac)2.\dfrac{f_c}{f_{c,m}}=\dfrac{4a_c}{\left(1+a_c\right)^2}.fc,m​fc​​=(1+ac​)24ac​​.

If, as normally assumed, the elastic limit of 80 %80~\%80 % of the maximum strength, then

fcfc,m=4ac(1+ac)2=0.8,ac≈3.73.\dfrac{f_c}{f_{c,m}}=\dfrac{4a_c}{\left(1+a_c\right)^2}=0.8,\qquad a_c\approx3.73.fc,m​fc​​=(1+ac​)24ac​​=0.8,ac​≈3.73.

For other ratios, aca_cac​ can be determined accordingly.

Determination of Parameters

The parameter gtg_tgt​ could be associated with the mode one specific fracture energy of the material. For concrete, it typically ranges from 40 N/m40~\mathrm{N/m}40 N/m to 120 N/m120~\mathrm{N/m}120 N/m (according to ABAQUS). Values of similar scale can be used.

The counterpart gcg_cgc​ can be chosen as several hundred times larger than gtg_tgt​.

The ata_tat​ can be set to (0, 1)(0,~1)(0, 1), typically, a value of 0.70.70.7 is good for general use. The aca_cac​ is greater than 111. A larger aca_cac​ has a narrower hardening region and thus degrades more rapidly. For high strength concrete, aca_cac​ can be large. For low strength concrete, aca_cac​ could be around 222.

material ConcreteExp 1 3E4 3. .6 4E-3 30. 4. 1E-1 .2

The above command has the following tension response (strain and stress).

And the following compression response.

SimpleHysteresis
tension response
compression response